Acquisition using simultaneous sources

Abstract

We present a technique in which two or more shots are acquired during the time it normally takes to acquire one shot. The two (or more) shots are fired in a near simultaneous manner with small random time delays between the component sources. A variety of processing techniques are applied to produce the same seismic images which would have resulted from firing the simultaneous shots separately. These processing techniques rely on coherency of the wavefield in the common-shot domain and unpredictability in the common-receiver, common-offset, and common-midpoint domains. We present results of its application on synthetic 2D, real 2D, and real 3D data from the Gulf of Mexico. These results demonstrate that, in deep water with modest water-bottom reflectivity, no special processing is required, whereas in shallower water with stronger water-bottom reflectivity, the use of shot-separation techniques is necessary. We conclude that this technique can be used robustly to improve source sampling and, for example, ...